JsonNode request with other language letters gets 400 error java

Question

I want to make a request with this link:

https://data.egov.kz/api/v4/gbd_ul/v1?apiKey=10232845919d49ac8eb22a8b8347fb1b&source={size:10,query:{bool:{should:[{prefix:{bin:"тов"}},{match:{namekz:"тов"}},{match:{nameru:"тов"}}]}}}

If i pass this on Postman i get a result list. (disable SslVerification)

But with my code i am getting an exception. "server returned status code 400"

But i can get a result if in request only english letters. But if i add other language letters, in this case "тов", i am getting an exception.

My code:

ObjectMapper mapper = new ObjectMapper();
        disableSslVerification();
StringBuilder request = new StringBuilder();
        request.append("https://data.egov.kz/api/v4/gbd_ul/v1?apiKey=10232845919d49ac8eb22a8b8347fb1b&source={");
        request.append("size:").append(limit).append(",query:{bool:{should:[");
        request.append("{prefix:{bin:\"").append(searchText).append("\"}},{match:{nameru:\"").append(searchText).append("\"}},{match:{namekz:\"").append(searchText).append("\"}}]}}}");
        JsonNode json = mapper.readValue(new URL(request.toString()), JsonNode.class);